// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <base/check.h>
#include <base/files/file.h>
#include <base/files/file_util.h>
#include <base/json/json_writer.h>
#include <base/logging.h>
#include <base/task/thread_pool/thread_pool_instance.h>
#include <base/values.h>
#include <brillo/flag_helper.h>

#include <string>

#include "ml_benchmark/json_serializer.h"
#include "ml_benchmark/memory_sampler.h"
#include "ml_benchmark/shared_library_benchmark.h"
#include "ml_benchmark/shared_library_benchmark_functions.h"
#include "ml_benchmark/sysmetrics.h"

using chrome::ml_benchmark::AccelerationMode;
using chrome::ml_benchmark::BenchmarkResults;
using chrome::ml_benchmark::CrOSBenchmarkConfig;
using chrome::ml_benchmark::Metric;
using ml_benchmark::PeakMemorySampler;
using ml_benchmark::SharedLibraryBenchmark;
using ml_benchmark::SharedLibraryBenchmarkFunctions;

namespace {

void AddMemoryMetric(const std::string& metric_name,
                     const int64_t value,
                     BenchmarkResults* results) {
  auto& metric = *results->add_metrics();
  metric.set_name(metric_name);
  metric.set_units(Metric::BYTES);
  metric.set_direction(Metric::SMALLER_IS_BETTER);
  metric.set_cardinality(Metric::SINGLE);
  metric.add_values(value);
}

void PrintMetrics(const BenchmarkResults& results) {
  for (const auto& latencies : results.percentile_latencies_in_us()) {
    std::string percentile = std::to_string(latencies.first);
    LOG(INFO) << percentile
              << "th percentile latency: " << latencies.second / 1000000.0
              << " seconds";
  }

  // Assume single values for now.
  for (const auto& metric : results.metrics()) {
    LOG(INFO) << metric.name() << ": " << metric.values()[0] << " ("
              << chrome::ml_benchmark::Metric_Units_Name(metric.units()) << ")";
  }
}

void BenchmarkAndReportResults(
    const std::string& driver_name,
    const base::FilePath& driver_file_path,
    const CrOSBenchmarkConfig& config,
    const base::Optional<base::FilePath>& output_path) {
  auto functions =
      std::make_unique<SharedLibraryBenchmarkFunctions>(driver_file_path);
  if (functions == nullptr || !functions->valid()) {
    LOG(ERROR) << "Unable to load the " << driver_name << " benchmark";
    return;
  }

  const int64_t initial_memsize = ml_benchmark::GetVMSizeBytes();
  const int64_t initial_rss_swap = ml_benchmark::GetSwapAndRSSBytes();
  const auto start_time = base::Time::Now();

  scoped_refptr<PeakMemorySampler> mem_sampler = new PeakMemorySampler();
  PeakMemorySampler::StartSampling(mem_sampler);

  LOG(INFO) << "Starting the " << driver_name << " benchmark";
  SharedLibraryBenchmark benchmark(std::move(functions));
  BenchmarkResults results;
  if (!benchmark.ExecuteBenchmark(config, &results)) {
    LOG(ERROR) << "Unable to execute the " << driver_name << " benchmark";
    LOG(ERROR) << "Reason: " << results.results_message();
    return;
  }

  PeakMemorySampler::StopSampling(mem_sampler);

  if (results.status() == chrome::ml_benchmark::OK) {
    LOG(INFO) << driver_name << " finished";

    const int64_t final_vmpeaksize = ml_benchmark::GetVMPeakBytes();
    const int64_t peak_rss_swap = mem_sampler->GetMaxSample();

    AddMemoryMetric("initial_vmsize", initial_memsize, &results);
    AddMemoryMetric("final_vmpeak", final_vmpeaksize, &results);
    AddMemoryMetric("initial_rss_swap", initial_rss_swap, &results);
    AddMemoryMetric("peak_rss_swap", peak_rss_swap, &results);

    auto* benchmark_duration = results.add_metrics();
    benchmark_duration->set_name("benchmark_duration");
    benchmark_duration->set_units(Metric::MS);
    benchmark_duration->set_direction(Metric::SMALLER_IS_BETTER);
    benchmark_duration->set_cardinality(Metric::SINGLE);
    benchmark_duration->add_values(
        (base::Time::Now() - start_time).InMillisecondsF());

    PrintMetrics(results);

    if (output_path) {
      ml_benchmark::WriteResultsToPath(results, *output_path);
    }
  } else {
    LOG(ERROR) << driver_name << " Encountered an error";
    LOG(ERROR) << "Reason: " << results.results_message();

    if (output_path) {
      ml_benchmark::WriteResultsToPath(results, *output_path);
    }
  }
}

}  // namespace

int main(int argc, char* argv[]) {
  DEFINE_string(workspace_path, ".", "Path to the driver workspace.");
  DEFINE_string(config_file_name, "benchmark.config",
                "Name of the driver configuration file.");
  DEFINE_string(driver_library_path, "libsoda_benchmark_driver.so",
                "Path to the driver shared library.");
  DEFINE_bool(use_nnapi, false, "Use NNAPI delegate.");
  DEFINE_string(output_path, "", "Path to write the final results json to.");

  brillo::FlagHelper::Init(argc, argv, "ML Benchmark runner");

  base::FilePath workspace_config_path =
      base::FilePath(FLAGS_workspace_path).Append(FLAGS_config_file_name);

  CrOSBenchmarkConfig benchmark_config;

  if (FLAGS_use_nnapi) {
    benchmark_config.set_acceleration_mode(AccelerationMode::NNAPI);
  }

  CHECK(base::ReadFileToString(workspace_config_path,
                               benchmark_config.mutable_driver_config()))
      << "Could not read the benchmark config file: " << workspace_config_path;

  base::Optional<base::FilePath> output_file_path;
  if (!FLAGS_output_path.empty()) {
    output_file_path = base::Optional<base::FilePath>(FLAGS_output_path);
    if (!output_file_path->IsAbsolute()) {
      output_file_path = base::Optional<base::FilePath>(FLAGS_workspace_path)
                             ->Append(FLAGS_output_path);
    }
  }

  base::ThreadPoolInstance::CreateAndStartWithDefaultParams("ml_benchmark");

  base::FilePath driver_library(FLAGS_driver_library_path);
  BenchmarkAndReportResults(FLAGS_driver_library_path, driver_library,
                            benchmark_config, output_file_path);

  LOG(INFO) << "Benchmark finished, exiting";
}